The Good Stuff
The rest of this website seems to be full of grim recollections of problems I had building the aircraft – which is a pity – because the aircraft is generally great to fly.
The following are some of the good things that I have been impressed with or pleased about.
The engine is running at about or slightly better fuel economy than the book figures. I have done a number of long trips at fairly high revs (2800 to 2900) and fuel consumption is 24 – 25litres an hour. At 75% settings (about 2700 RPM) it is burning 21.5 litres an hour. The trade off is that it runs best temperatures at 2900 RPM.
At these RPMs I am getting 110 – 115 knots (TAS) below about 4500 ft and above that 115 – 120 knots (TAS) reliably.
Take off and landing distances.
Jabiru give very conservative figures for the distances required (as they should). Essentially they say 520m at standard conditions at max weight. Obviously this should be your planning distances.
What I have found is a much more impressive aircraft. I did some very rough tests at near max weight, sea level and a temperature of 25 degrees centigrade. (Density Altitude of 1200 ft on that day). Conditions on the day were grass strip, a bit rough, dry short grass and a headwind of about 3 knots.
Landing to full stop distance from threshold (although actually touched down past the threshold) about 250 metres no brakes used.
Take off from threshold (starting position) to wheels off – less than 200 metres.
Handling at various loads
I have used my aircraft at lots of various all up weights and it performs well at all. Obviously at low weights she is much quicker and wants to fly very early. Climb figures are quite amazing. With just pilot, full fuel and DA like the one quoted above it can climb out well in excess of 1000 feet minute. At full weight she climbs in excess of 750 feet a minute. But again the trade off with these climbs is she does get increased temperatures. If I use lower climb out angles she easily gets 500 feet a minute with low temperatures
One thing I have learned though is that when it comes time to raise the flaps from take off position she does tend to lose lift noticeably. She has this great climb rate, then she staggers to maintain height till she picks up speed then she is off again into a good climb. I now lift flap in stages and she handles it very well.
Cross wind capability
The book value is 14 knots crosswind. Again this is very conservative. Despite being small and easily buffeted about she is very controllable above that speed – I am not endorsing it or recommending it! But I have been caught a few times where the situation has forced me to do a crosswind in excess of this with no options to go elsewhere. Obviously in crosswinds you need to do landings with less flap (or no flap) and with faster speeds)
Top wind speed: 34 knots from the left onto the main runway at Longreach. Very hairy, not pretty and once I touched down I saw left side, right side and centre line up "close and personal" but we landed safely.
I am not recommending planning to land above the factory limits but if you get stuck and have to you will know she handles it pretty well.
A hint about touch and goes.
This aircraft wants to fly! If you have any rear deflection on the joy stick when you add power during a touch and go she will want to take off, even at low speed.
I managed to do this twice, once in another Jabiru when I was getting up my hours and once in mine. Very scary to have her jump into the air and immediately have the stall warning squarking in your ear.
What I now do is always a slow controlled Touch and Go
1Once nose wheel is on the ground – FULL FORWARD on the stick 2Wait till full control on pedals then power to full 3Gradually return the stick to neutral 4Check airspeed and then do normal lift off.
This aircraft is so docile in the stall when I did the initial stall test I couldn’t tell when it stalled. The stall warning came on, then she got sluggish then I had to look at the VSI to be sure she was actually descending.
I once managed to get it to begin to drop the left wing but as a rule it did not.